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[Qemu-devel] [PATCH] qcow2: Restore total_sectors value in save_vmstate
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH] qcow2: Restore total_sectors value in save_vmstate |
Date: |
Sun, 20 Oct 2013 20:28:20 +0200 |
Since df2a6f29a5, bdrv_co_do_writev increases the total_sectors value of
a growable block devices on writes after the current end. This leads to
the virtual disk apparently growing in qcow2_save_vmstate, which in turn
affects the disk size captured by the internal snapshot taken directly
afterwards through e.g. the HMP savevm command. Such a "grown" snapshot
cannot be loaded after reopening the qcow2 image, since its disk size
differs from the actual virtual disk size (writing a VM state does not
actually increase the virtual disk size).
Fix this by restoring total_sectors at the end of qcow2_save_vmstate.
Signed-off-by: Max Reitz <address@hidden>
---
block/qcow2.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/block/qcow2.c b/block/qcow2.c
index c1abaff..5c05bb5 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1939,6 +1939,7 @@ static int qcow2_save_vmstate(BlockDriverState *bs,
QEMUIOVector *qiov,
int64_t pos)
{
BDRVQcowState *s = bs->opaque;
+ int64_t total_sectors = bs->total_sectors;
int growable = bs->growable;
int ret;
@@ -1946,6 +1947,10 @@ static int qcow2_save_vmstate(BlockDriverState *bs,
QEMUIOVector *qiov,
bs->growable = 1;
ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov);
bs->growable = growable;
+ // bdrv_co_do_writev will have increased the total_sectors value to include
+ // the VM state - the VM state is however not an actual part of the block
+ // device, therefore, we need to restore the old value.
+ bs->total_sectors = total_sectors;
return ret;
}
--
1.8.3.1
- [Qemu-devel] [PATCH] qcow2: Restore total_sectors value in save_vmstate,
Max Reitz <=